When an Endobronchial Mass Is Not a Tumor: An Occult Foreign Body Causing Lobar Collapse in an Adolescent
2Pediatric Department, Soroka Medical Center, Israel
Background
Foreign-body aspiration is predominantly encountered in young children and is less commonly suspected in adolescents, particularly without a witnessed aspiration event. Delayed diagnosis may result in persistent bronchial obstruction, granulation tissue formation, and lobar collapse, potentially mimicking an endobronchial neoplasm.
Methods
We retrospectively reviewed the clinical course, pulmonary function tests, serial chest radiographs, computed tomography (CT), bronchoscopic findings, treatment, and radiographic follow-up of a 16-year-old boy with end-stage renal disease undergoing hemodialysis who presented with persistent respiratory symptoms and impaired pulmonary function.
Results
Pulmonary function testing demonstrated a restrictive ventilatory defect, with total lung capacity and vital capacity reduced to 61% and 60% predicted, respectively. Diffusing capacity for carbon monoxide (DLCO) was reduced to 49% predicted, with reduced alveolar volume and relatively preserved transfer coefficient.
Serial radiographs obtained during recurrent hospital admissions documented the interval development and persistence of left lower lobe collapse. Bronchoscopy revealed an obstructing, bleeding endobronchial lesion initially suspected to represent a tumor. CT performed the same day demonstrated a sharply marginated, hollow endobronchial structure with surrounding air and adjacent soft-tissue thickening consistent with granulation tissue. These findings favored an aspirated foreign body rather than a primary endobronchial neoplasm. Repeat bronchoscopy enabled removal of a plastic pen cap. Follow-up radiography demonstrated substantial, although incomplete, re-expansion of the left lower lobe.
Conclusions
Retained foreign bodies may become embedded in vascular granulation tissue and mimic a bleeding endobronchial tumor. Plastic objects may be radiographically occult; CT recognition depends on their geometry, air interfaces, relationship to the bronchial lumen, and secondary obstructive changes. An occult foreign body should therefore remain in the differential diagnosis of newly developed persistent unilateral lobar collapse in children and adolescents, even without a recalled aspiration event.